1. Field of the Invention
The present invention relates to a honeycomb catalyst and a manufacturing method therefor and, more particularly, to a honeycomb catalyst having an improved gas contact efficiency and a manufacturing method therefor.
2. Description of Related Art
Honeycomb catalysts having a grid-like or beehive-like opening have widely been used as catalysts for reaction with various gases such as NOx removal catalysts for boiler exhaust gas and gas turbine exhaust gas of various fuels or catalysts for treating automotive exhaust gas because they can maintain a low pressure loss when gas flows through and comes into contact with the catalyst and because clogging can be avoided in treatment of gas containing dust.
The honeycomb catalyst used here is conventionally manufactured as follows: For example, for an NOx removal catalyst, a solution of compound of V, Mo, W, etc., which are active components, an organic binder, and an inorganic binder are mixed with TiO.sub.2 powder, which is a catalyst raw material, and the mixture is kneaded into a clay-like substance, and then a molded product having a grid-like opening is obtained by using an extrusion molding machine provided with a mold 10, for example, as shown in FIGS. 7 and 8. FIG. 7 is a front view, and FIG. 8 is a sectional view taken along the line VIII--VIII of FIG. 7. The clay-like substance containing a catalyst component passes through a clay-like substance passing hole 12 from B side toward C side in FIG. 8 and is pushed out from a gap of a honeycomb-shaped mouthpiece tip end 11 to yield a honeycomb product having square openings. Reference numeral 13 in FIGS. 7, 8 denotes a bolt hole for attaching a mouthpiece 10 to an extruder, and 14 denotes a bolt hole for attaching a die forming an external frame.
Although the honeycomb catalyst has excellent structural features as described above, a honeycomb catalyst which has an improved gas contact efficiency has been demanded to carry out gas reaction or gas treatment more efficiently.